per-Application IP Address / IP Access Control

[wind.gmbh]

By default, a Cloudron App will be served on all Interfaces.
Therefore, if any Cloudron App is required to be reachable by the public internet, all Cloudron Apps on the host will be reachable by the public internet.

server {
    listen       443 ssl http2;
    server_name  application.cloudron-host.example.com;
    listen       [::]:443 ssl http2;
}

It would be great if it was possible to assign a dedicated IP address that an application will exclusively listen on.
That way, the application could be hidden from the public internet by restricting access to it on a network firewall.

server {
    listen       10.10.10.10:443 ssl http2;
    server_name  application.cloudron-host.example.com;
    listen       [fdea:dbee::f]:443 ssl http2;
}

Another way of achieving a similar goal on a single IP address/ all interfaces would be IP access control lists in the reverse proxy:

server {
    listen 443 ssl http2;
    server_name application.cloudron-host.example.com;
    listen [::]:443 ssl http2;
    allow 192.168.1.0/24; # Allowed Access
    deny all;
}

I know that this is probably a lot more work to implement in the front end, than in these quick examples.
But anyway, these features are probably something that possibly other users would appreciate.

[girish]

@wind-gmbh Is the use case here that the server has multiple interfaces and one is public internet and another is private internet ? In that case, you want to configure the app(s) to listen only on the private internet interface? Did I get the use case right?

FWIW, I prefer the first config more then the second one i.e just restrict listening on the interface only in the first place.

[wind.gmbh]

@girish said in per-Application IP Address / IP Access Control:

@wind-gmbh Is the use case here that the server has multiple interfaces and one is public internet and another is private internet ?

Yes, exactly. It is basically the idea to limit the attack surface in a single-server scenario by excluding some apps from the public eye.

@girish said in per-Application IP Address / IP Access Control:

FWIW, I prefer the first config more then the second one i.e just restrict listening on the interface only in the first place.

I would say either has it's advantages:

	listen on IP	allow / deny
Network Layer	Layer 3/4 (TCP/IP)	Layer 7 (HTTP)
Works with single IP	no	yes
Network segmentation / Firewall required	yes	no
Visible Access Barrier	Not routed / dropped by Firewall	HTTP 403
Cloudron needs to keep track of assigned IP addresses	yes	no

They are differently working solutions for the same basic problem, that apply to different scenarios.